With the replacement pump module on the International Space Station’s S1 truss declared healthy and ready for operation following Monday’s 7-hour, 20-minute spacewalk by Expedition 24 Mission Specialists Doug Wheelock and Tracy Caldwell Dyson, ground controllers began configuring station systems in the first of three days of work to fully reactivate the revived Loop A cooling system.

This image photographed by an Expedition 24 crew member on the International Space Station is centered on the NASA Lyndon B. Johnson Space Center located in the southeastern Houston metropolitan area. Credit: NASA

Loop A was repressurized late Monday afternoon and the ammonia pump module was spun up and began running normally. A quick data review of pump performance indicated no problems. It is anticipated that the station will be back in its normal configuration for standard operations by Thursday.

To begin bringing the system fully back on line, Loop A was powered down Tuesday morning to allow Mission Specialist Shannon Walker to remove a contingency power jumper that had been routing cooling to systems from Loop B since July 31 when the pump module failed. Afterwards, flight controllers began the process of reactivating Loop A and the spare pump module to enable the continuation of systems reconfiguration. By 9:45 a.m. EDT, the loop was up and running again.

Otherwise, the Expedition 24 crew had a light-duty day Tuesday to regroup and recharge following Monday’s spacewalk, the third in a series of excursions that began Aug. 7 to remove and replace the failed pump module. In the early afternoon, the crew spoke with specialists in Houston for a debrief of the spacewalk.

On Wednesday at 4:30 p.m. the thrusters of the docked ISS Progress 38 cargo craft will be fired for nearly 11 minutes to boost the perigee of the station’s orbit by about three statute miles. This will put the complex in the proper position for the arrival of ISS Progress 39 and the departure of Caldwell Dyson, Commander Alexander Skvortsov and Mission Specialist Mikhail Kornienko aboard Soyuz TMA-18 in September.